The present disclosure relates generally to systems for forming multi-layer films. In one particular exemplary embodiment, the present disclosure relates to systems for forming multi-layer films using corona treatments to increase interlayer adhesion.
Corona treatment of films is a cost-effective technique for modifying surface properties of the given films. The term “corona” as used herein refers to a process in which active gaseous species (e.g., free radicals, ions, and electrically or vibrationally excited states) are produced by electron impact with gaseous molecules. The term “corona” is also commonly referred to by other terms, such as corona discharge, barrier discharge, atmospheric-pressure dielectric-barrier discharge, atmospheric-pressure plasma, atmospheric-pressure glow discharge, atmospheric-pressure non-equilibrium plasma, silent discharge, atmospheric-pressure partially ionized gas, filamentary discharge, direct or remote atmospheric-pressure discharge, externally sustained or self-sustained atmospheric-pressure discharge, and the like.
During or after a corona treatment process, the corona-treated film is typically exposed to air prior to a subsequent coating process. The exposure to air, particularly oxygen, even for short durations, may reduce the surface properties of the film. This may reduce interlayer adhesion between the treated surface and a subsequent coating. One common technique for removing air during a corona-treatment process involves generating a vacuum and operating at pressures below standard atmospheric pressure. However, vacuum processes commonly have high operating and capital costs, and typically require the treated film to be removed from the vacuum environment prior to subsequent coating processes. As such, there is an ongoing need for efficient systems for forming multi-layer films with corona treatments that minimize exposure of the energized surfaces to oxygen-containing environments prior to subsequent coating processes.